Merge pull request #16190 from oss92/word_truncation

Word truncation

3 files changed, 49 insertions, 0 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 214722a0e5..f6d152174f 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Add `String#truncate_words` to truncate a string by a number of words.
+
+    *Mohamed Osama*
+
 *   Deprecate `capture` and `quietly`.
 
     These methods are not thread safe and may cause issues when used in threaded environments.
diff --git a/activesupport/lib/active_support/core_ext/string/filters.rb b/activesupport/lib/active_support/core_ext/string/filters.rb
index 49c0df6026..1dfaf76673 100644
--- a/activesupport/lib/active_support/core_ext/string/filters.rb
+++ b/activesupport/lib/active_support/core_ext/string/filters.rb
@@ -62,4 +62,28 @@ class String
 
     "#{self[0, stop]}#{omission}"
   end
+
+  # Truncates a given +text+ after a given number of words (<tt>words_count</tt>):
+  #
+  #   'Once upon a time in a world far far away'.truncate_words(4)
+  #   # => "Once upon a time..."
+  #
+  # Pass a string or regexp <tt>:separator</tt> to specify a different separator of words:
+  #
+  #   'Once<br>upon<br>a<br>time<br>in<br>a<br>world'.truncate_words(5, separator: '<br>')
+  #   # => "Once<br>upon<br>a<br>time<br>in..."
+  #
+  # The last characters will be replaced with the <tt>:omission</tt> string (defaults to "..."):
+  #
+  #   'And they found that many people were sleeping better.'.truncate_words(5, omission: '... (continued)')
+  #   # => "And they found that many... (continued)"
+  def truncate_words(words_count, options = {})
+    sep = options[:separator] || /\s+/
+    sep = Regexp.escape(sep.to_s) unless Regexp === sep
+    if self =~ /\A((?:.+?#{sep}){#{words_count - 1}}.+?)#{sep}.*/m
+      $1 + (options[:omission] || '...')
+    else
+      dup
+    end
+  end
 end
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index 515144245a..2ece20d379 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -229,6 +229,27 @@ class StringInflectionsTest < ActiveSupport::TestCase
     assert_equal "Hello Big[...]", "Hello Big World!".truncate(15, :omission => "[...]", :separator => /\s/)
   end
 
+  def test_truncate_words
+    assert_equal "Hello Big World!", "Hello Big World!".truncate_words(3)
+    assert_equal "Hello Big...", "Hello Big World!".truncate_words(2)
+  end
+
+  def test_truncate_words_with_ommission
+    assert_equal "Hello Big World!", "Hello Big World!".truncate_words(3, :omission => "[...]")
+    assert_equal "Hello Big[...]", "Hello Big World!".truncate_words(2, :omission => "[...]")
+  end
+
+  def test_truncate_words_with_separator
+    assert_equal "Hello<br>Big<br>World!...", "Hello<br>Big<br>World!<br>".truncate_words(3, :separator => '<br>')
+    assert_equal "Hello<br>Big<br>World!", "Hello<br>Big<br>World!".truncate_words(3, :separator => '<br>')
+    assert_equal "Hello\n<br>Big...", "Hello\n<br>Big<br>Wide<br>World!".truncate_words(2, :separator => '<br>')
+  end
+
+  def test_truncate_words_with_separator_and_ommission
+    assert_equal "Hello<br>Big<br>World![...]", "Hello<br>Big<br>World!<br>".truncate_words(3, :omission => "[...]", :separator => '<br>')
+    assert_equal "Hello<br>Big<br>World!", "Hello<br>Big<br>World!".truncate_words(3, :omission => "[...]", :separator => '<br>')
+  end
+
   def test_truncate_multibyte
     assert_equal "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 ...".force_encoding(Encoding::UTF_8),
       "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 \354\225\204\353\235\274\353\246\254\354\230\244".force_encoding(Encoding::UTF_8).truncate(10)